The accident rate for bike lanes is higher per mile than streets with no bike lanes. The reason is that bike lanes create more places where cars and bikes have to cross each other's path. 90% of car-bike crashes are at places the travel paths cross, so, naturally, more crossings equal more accidents.

That said, "Fear from the Rear" (being afraid you will get hit from behind) is huge for many cyclists, especiall new ones. Bike lanes do a decent job of helping prevent cyclists getting rear-ended, so a lot of novices and others advocate for lanes to alleviate this fear.

Educating motorists and cyclists how to share the road is, in the long run, the ideal solution, but many folks are too scared to ride without bike lanes.